Non-silver halide light sensitive materials



Ma y 16, 1967 w. T. HANSON, JR. ETAL 3,

NON-SILVER HALIDE LIGHT SENSITIVE MATERIALS Filed March 19, 1963 SUPPORT EMULSION LAYER SILVER HAL/DE SOLVENT AND DEVELOPING AGENT EXPOSED PRINT FORMING LAYER NUCLEI SILVER IMAGE SUPPORT BRUSH SILVER NITRATE SOLUTION EXPOSED PRINT FORMING LAYER NUCLEI SUPPORT DEVELOPING SOLUTION EXPOSED PRINT FORMING LAYER NUCLEI SILVER IMAGE SUPPORT 19 4 DEVELOP/N6 SOLUTION 20 I /SILVER COMPLEX/N6 COMPOUND C EXPOSED PRINT FORM/N6 LAYER' 1M NUCLEI SILVER IMAGE SUPPORT Wesleyl. Hanson,Jn 1

QIohn/ Williams Q MM/INVENTORS United States Patent OfiFice 3,320,064 Patented May 16, 1967 3,320,064 N ON-SILVER HALIDE LIGHT SENSTTIVE P/IATERIALS Wesley T. Hanson, Jr., and John Williams, Rochester,

N.Y., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Filed Mar. 19, 1963, Ser. No. 266,328

2%] Claims. (Cl. 96-49) This invention relates to light-sensitive photographic materials and in particular to materials which form a latent image comprising particulate centers or nuclei capable of physical development to a visible silver or other metallic image.

It is well known in certain photographic systems such as diffusion transfer, to employ dispersed particulate matter (often referred to as nuclei or fogging agents) as centers for physical development. These nuclei, however, are not themselves involved in the formation of the latent image, but merely offer convenient centers for a kind of electrolytic plating out of metal ions. The nuclei are under the control of a developing or developed image generated independently, for example, by exposure of a silver halide gelatin photographic emulsion in the same or a juxtaposed layer. Such silver halide emulsions are usually opaque, relatively thick, and can be chemically developed. However, high image resolution in processes of this type, has been diflicult to obtain since lateral diffusion of solubilized silver halide usually occurs during transfer to the receiving layer from unexposed areas of a developed lightsensitive contacting emulsion layer.

We have discovered a way in which a light-sensitive layer is provided comprising physically developable nuclei associated with a photosensitive substance which on exposure to actin-ic radiation renders the nuclei inert so that a direct positive image is obtained on exposure and physical development.

One object of our invention is to provide a light-sensitive material capable of producing silver or other metallic photographic image in the unexposed regions by physical development.

Another object is to provide a simplified direct positive photographic process. A further object is to provide a photographic material which is developable by physical development, uniformly developable without exposing and containing a light-sensitive component which renders the exposed areas inert to physical development. A still further object is to :provide processes for silver development of the non-silver halide light-sensitive layers after exposure. An additional object is to provide a light-sensitive material which is inert to conventional chemical development.

A further object is to provide a material in which the mass and optical density of the light-sensitive ingredient is exceedingly small compared to the mass and optical density of the resulting photographic image.

Another object is to provide light-sensitive or photoreactive elements which can function as silver receiving layers after exposure. Other objects will be evident from this specification and the claims which follow.

(2 aminophenylazo) N [5 (2,4 di

We have accomplished these objects by preparing sensitized layers containing a dispersion of particles having an average diameter of 72,50O A. which are centers for physical development. These physical development centers can be formed in a number of ways. In one embodiment of our invention, We may use the Well-known nucleating agents for diffusion transfer processes such as particles of silver, metal sulfides, metal selenides, silver proteinate, etc.

Typical nucleating agents useful in our invention include Carey Lea Silver, the colloidal sulfides and selenides of the metals of Groups I-B, HB, IV-B, and VIII of the Periodic Table, e.g. zinc, cadmium, nickel, etc.

A dispersion of these nuclei in a water-permeable hydrophilic binder can be coated on a suitable support of preferably from 0.001 to 5 milligrams per square foot. In the same or a juxtaposed layer is contained a compound or combination of compounds which on exposure to light effectively desensitizes the closely associated nuclei and renders them inert to physical development. We may use a photoreactive combination of an azide with a coupler or else use a .polysultide which is photoreactive. Practical concentrations of coupler, such as l-hydroxy-4-(1-phenyl- 5 tetrazolylthio) N [5 (2,4 di tert amylphenoxy)- n-butyl] -2-naphthamide,

corvnwmmQ-omm may be from .05 to .25 gram per square foot.

For use with 4-azido-3-methyl-N,N-diethylaniline, We prefer the following couplers, for example, l-hydroxy-4- tert amylphenoxy)butyl]-2-naphthamide,

C sHu 3 hydroxy 4 (2 acetamidophenylazo) N [6 (2,4- li-tert-amylphenoxy) butyl] 2-naphthamide,

N H N NHOOCH:

l-hydroxy-4-(4-benzotriazolylazo)N-[6-(2,4-di-tert-amylp'henoxy) butyl] 2-naphthamide,

The couplers used are not critical providing they release an inhibiting fragment. Among the couplers which may be used are those disclosed in US. patent applications Whitmore et al., Ser. No. 804,219 filed April 6, 1959, now US. Patent No. 3,148,062, and Barr et al., Ser. No. 817,- 860 filed June 3, 1959, now abandoned.

Polysulfides may be used, preferably for example:

which does not require an azide but forms a desensitizing agent by exposure to light.

The azides which are operative in our invention are only those which are photoreactive in reaction with one or more of the above couplers to form or release an inhibiting fragment which inactivates the nuclei to physical development such as for example, our preferred species, 4-azido-3-methyl-N,N-diethylaniline.

By reference to the accompanying drawing, methods by which light-sensitive layers of the invention can be developed will be apparent, for example:

FIG. 1 shows development by contact with an unexposed silver halide emulsion layer in the presence of a silver halide solvent and silver halide developing agent.

FIG. '2 shows a method of treatment comprising brushing a light-sensitive layer of the invention after exposure with a brush 17 containing a silver nitrate solution 18.

FIG. 3 shows the development of the AgNQ treated layer of FIG. 2 with a developing solution 19, to produce a silver image 16.

FIG. 4 shows development of an exposed layer in which a light-sensitive nuclei composition 12 and a silver complex-compound 20 are contained in a binder 11 on a support whereby a silver image 16 is produced in said layer, by treatment with a silver halide developing solution 19.

The following typical reaction shows the operation of light on an azide (Compound II) to activate a thioether coupler resulting in freeing lphenyl-S-mercapto-tetrazole (Compound I).

(Compound II) OONHR 1 1 s l @"l t N:N

s o l H 0 -CONHR t r N:

(Compound I) \l Cyan dye Appropriate couplers include those known in the photographic art as Development Inhibitor Releasing (DIR) couplers which react with the oxidation products of silver halide developers. Light sensitive azides on exposure to light react with these DIR couplers to yield compounds which inhibit the nuclei to physical development.

The DIR coupler compounds of the invention include well-known coupler compounds such as phenolic, naphtholic, 5-pyr-azolone and open-chain reactive methylene compounds containing the group X-CH -Y wherein X and Y are groups activating the methylene group, as present in couplers containing the group Some DIR couplers contain a preformed developmentinhibiting moiety such as a tetrazole or triazole group. Similarly, organic radicals may be joined to the coupling position of the coupler molecule by a S linkage which is broken on coupling with the active species of the azide to yield mercapto compounds which function as physical development-inhibiting substances. These DIR couplers are described below in relation to their reactions with the oxidation products of silver halide developers.

An additional type of DIR coupler constituting an illustrative embodiment of the invention contains in the coupling position a chain of atoms which, during reaction of the coupler with the azide, cyclizes to form a development-inhibiting substance.

The development-inhibiting moieties of the coupler compounds thus include groups of atoms suitably linked to the coupling position of the couplers so as to yield physical development-inhibiting substances during the exposure of the light-sensitive coating providing a suitable azide is present. These moieties include triazolyl, tetrazolyl, thiazolyl, mercaptotetrazolyl, etc., radicals linked to the couplers in the coupling position by azo linkages; 0- amino and o-amido monocyclic aryl azo radicals and 0- amino and o-amido monocyclic aryl azoxy, and triazolyloxy radicals, as well as monocyclic arylthio, alkylthio and heterocyclicthio radicals linked to the couplers in the coupling position such as alkylthio, phenylthio, naphthylthio, substituted alkylthio, phenylthio, and naphthylthio; thiazolylthio, and tetrazolylthio radicals.

7 -hydroxy-4- (4-benzotriazolylazo) -N-[6-(2,4-di-tertamylphenoxy) butyl] -2-naphth amide N s \N/ l-hydroxy-4- [fl- (4-benzotriazolyl) ethoxy] -N- [5- (2,4-ditert-amylphenoxy butyl] -2-naphthamide 3-carboxymethyl-5-(4-dodecyloxyphenylazo)rhodanine HOOC CHzN-C=0 In preparing the light-sensitive elements, one of inorganic compounds referred to above as nuclei is dispersed in a suitable binder and then the mixture is coated on a support using any of the known coating methods. Suitable supports can be any of the known materials for this purpose, such as film base (e.g. cellulose nitrate film, cellulose ester film, etc.), plastic supports (e.g. polyethylene, polyethylene terephthalate, etc.), paper, metal, glass and the like.

Suitable binders for incorporating the present inorganic compounds can include any of the water-permeable materials, such as gelatin or other hydrophilic materials, such as collodion, albumin, cellulose derivatives, certain synthetic resins (polyvinyl alcohol), and the like.

In preparing light-sensitive print-forming layers the particular inorganic compound in question is formed and then after suitable washing, a slurry of the compound is dispersed in a binder, such as gelatin, in preparation for coating on a support.

In one method of practice of the invention, a print is formed in a light-sensitive layer of the invention by (1) exposing said layer to an actinic light source from be hind an imagewise transparency having opaque areas, and (2) developing said layer after exposure by contacting with an unexposed silver halide emulsion layer in the presence of a silver halide solvent and silver halide developing agent. After a brief contacting period of, say, about 30 seconds, the layers can be separated showing a silver image in the exposed light-sensitive layer corresponding to the unexposed portions thereof.

Another manner in which the light-sensitive layers of the invention can be developed comprises swabbing with an aqueous silver salt solution such as a dilute silver nitrate solution and then immersing the swabbed layer in a photographic developing solution followed by washing the developed print with water to stabilize it. Other methods for development of exposed layers of the invention comprise incorporating in said layers a silver complexing compound, such as silver-thiosulfate complex or the silver salt of 4,5-dihydroxy hexahydro-l,7-dioxa- 7a-hydroxymethyl-3-azaindene-2-thione, and the like. In processes where a silver complexing agent is incorporated in the sensitive layer, such layers are developed by treatment with a suitable silver halide developing solution.

In developing the exposed layers of the invention containing a silver complexing agent, any of the usual developing agents can be used such as N-monomethyl-paminophenol sulfate; dihydroxybenzene; hydroquinone, p-phenylenediamine developers; hydroquinone compounds (e.g. chlorohydroquinone, dichlorohydroquinone, bromohydroquinone, etc.); l-phenyl-S-pyrazolidone and its derivatives; triaminophenols; and the like.

Silver halide solvents for use in the physical developing process of the invention include alkali metal thiosulfates, ammonium thiosulfate, alkali metal thiocyanate, ammonium thiocyanate, sodium sulfite, etc.

Actinic light exposing sources can be any suitable tungsten source such as a Kodak No. 2 Photoflood Lamp, electrically heated incandescent filaments, and the like. However, heat may also be used to activate the coating of our invention using the exposing methods of thermography.

Silver halide emulsions useful in developing the exposed sensitive layers of the invention can comprise any of the conventional gelatino silver halide developing-out emulsions, e.g. gelatino silver chloride, -chlorobromide, -chloroiodide, -chlorobromoiodide, -bromide, and bromoiodide developing-out emulsions. The emulsions for use in the invention include emulsions having a silver halide carrier other than gelatin, for example, collodion, albumin, synthetic resins, and the like. These emulsions can be coated in the usual manner on a suitable support, e.-g. glass, cellulose nitrate film, cellulose ester film, paper, or metal, etc. The emulsions used for physical development can contain sensitizers or other addenda for improving the character of the emulsion as is well known in the art. The silver halide emulsions useful in the process of the invention can be prepared according to known methods such as those described in Hewitson and McClintock, US. Patent 2,618,556, issued Nov. 18, 1952, for example.

The wet thickness of such coatings can be in the range from about 0.001 to about 0.01 inch with a preferred wet thickness in the range from about 0.003 to about 0.006 inch. Thicker coatings can also be employed without detracting from the invention. Coatings as thin as those formed with a layer of evaporated nuclei are also useful.

The invention will now be further illustrated by way of the following examples.

EXAMPLE 1 A light-sensitive layer of the invention was prepared as follows:

(A) Coating:

4-azido-3-methyl-N,N-diethylaniline mg 500 l-hydroxy-4-(l-phenyl-S-tetrazolylthio)-N [6- The above was milled in a Waring Blendor for 4 minutes and the following added:

Mucochloric acid ma 200 Ethyl alcohol (95%) ml 1 Octylphenoxypolyethylene oxide ml 5 A coating was made with a .006 inch blade.

(C) Developer: G. Elon 5 Hydroquinone Sodium sulfite 72 Sodium metaborate 48 Sodium hydroxide 3.5 Ammonium thiosulfate 10 Water to one liter.

Other physical developers which are typical of those which may be used are as follows:

Developer Silver-ion concentration 4X10 M; pH 12.0; temp.

Solution A:

Deaerated distilled water ml 800 Developing agent, [4-amino-3-methyl-N-ethyl- N-(fi-methylsulfonamidoethyl) aniline sesquisulfatemonohydrate] g 2.25

Tribasic potassium phosphate g 50.00

Solution B:

Potassium chloride 0.61 g. dissolved in 50 ml. distilled water. Silver nitrate 0.61 g. dissolved in 50 ml. distilled water.

The AgCl is precipitated and allowed to stand in a dark bottle. The supernatant liquid is decanted and the precipitate dissolved in a solution of 6.20 g. of sodium thiosulfate pentahydrate dissolved in 100 ml. of distilled water.

Solutions A and B were mixed and diluted to a final volume of 1000 ml. 6 N sulfuric acid was used to adjust the pH to 12.00.

Developer Silver-ion concentration 1 10- M; pH 11.0; temp.

Solution A:

Deae r ated distilled water ml 800 Elon developing agent g 0.444 Hydroquinone g 0.284 Dibasic potassium phosphate g 50.00

Solution B: Same as for Solution B of the previous developer in this example except that a solution of 10.50 g. of sodium thiosulfate pentahydrate in 100 ml. of distilled water was used to dissolve the AgCl.

Solutions A and B are mixed and diluted to 1000 ml.

1O 5% aq. sol. propylated naphthalene sulfonate ml 5 Carey Lea Silver mg 1.7 0 ml 20 Saponin (7.5% aq. sol.) ml 5 The above was milled in a Waring Blendor for 4 minutes and filtered. The following mixture was added:

Mucochloric acid mg 200 ethyl alcohol ml 1 Octyl phenoxy polyethylene oxide ml 5 A coating was made with a .006 inch blade.

(B) Process: The film was exposed to ultraviolet light for 1 minute through a step tablet. The exposed strip and a strip of unexposed fine-grain positive film were dipped in developer (C) for 10 seconds and squeegeed in contact. After 5 minutes, the strips were separated. A positive image was formed on film (A).

E 0 to 1 liter.

The mechanism of our invention has not been established. However, it is believed that in physical development onto nuclei the nucleus acts as a carrier or conductor for the electron liberated by the reducing agent to enable it to make effective contact with the cation, e.g. silver ion, which is thereby reduced to metallic silver and deposited on the nucleus. It is hypothesized that the desensitizing agent, formed or liberated by the action of light, deposits on the surface of the colloidal particle and etfectively insulates it from conductive contact with either the precipitating cation, the reducing agent, or both, so that the redox reaction is retarded and/or does not take place effectively on the surface of the nuclei.

In the above application, our examples have been specific to images formed by physical development in which silver is used to form an image. However, other metals are known for use in physical development and could be used for the same purpose as silver by the appropriate substitution of metallic salts. Metals which are members of the electromotive scale below hydrogen are those which are most commonly employed for this purpose and include copper, arsenic, antimony, platinum, gold, mercury, silver and the like. The use of these metals to form images is within the scope of this invention. It has not been practical to show an example for each and every one of these metals, but silver images are believed to be those most preferred and to be typical of the phys ical development within the scope of this invention to obtain a metallic image.

It will be appreciated that the photoreactive elements prepared according to our invention are prepared under darkroom conditions as required.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

We claim:

1. A non-silver halide photographic element comprising a support having thereon light insensitive physically developable nuclei and a compound or combination of compounds which upon exposure to light forms or releases a desensitizing agent which causes the nuclei to be deactivated for physical development.

2. A photographic element of claim 1 having thereon colloidal silver nuclei.

3. A photographic element of claim 1 in which the compound is an organic sulfur compound which upon exposure to light causes the nuclei to form deactivated sites for physical development.

4. A photographic element of claim 1 in which the combination of compounds is a mixture of a light sensitive azide and a thioether coupler which upon exposure to light causes the nuclei to form deactivated sites for physical development.

5. A photographic element of claim 1 in which the combination of compounds is a mixture of 4-azido-3- methyl-N,N-diethylaniline, and a thioether coupler which upon exposure to light causes the nuclei to form deactivated sites for physical development.

6. A photographic element of claim 1 in which the compound is a photoreactive polysulfide compound which, on exposure to light, causes the nuclei to form deactivated sites for physical development.

7. A photographic element of claim 1 in which the combination of compounds is a mixture of an azide and a DIR coupler which upon exposure to light causes the nuclei to be deactivated for physical development.

8. A photographic element of claim 1 containing colloidal silver nuclei and a mixture of an azide and a DIR coupler which upon exposure to light causes the nuclei to form deactivated sites for physical development.

9. A photographic element of claim 1 containing colloidal silver nuclei and a polysulfide which upon exposure to light causes the nuclei to form deactivated sites for physical development.

10. A photographic element of claim 1 in which the compound is a polysulfide having the following structure:

HsC- CH3 which upon exposure to light causes the nuclei to form deactivated sites for physical development.

11. A photographic element of claim 1 in which the combination of compounds is a mixture of 4-azido-3- methyl-N,N-diethylaniline and a DIR coupler which upon exposure to light causes the nuclei to form deactivated sites for physical development.

12. A photographic element of claim 1 containing colloidal silver nuclei and a polysulfide having the following structure:

s- S- s 1130- CHa which upon exposure to light causes the nuclei to form deactivated sites for physical development.

13. A photographic element of claim 1 containing colloidal silver nuclei and a mixture of 4-azido-3-methyl- 12 N,N-diethylaniline and a DIR coupler which upon exposure to light causes the nuclei to form deactivated sites for physical development.

14. A process for preparing a positive metallic image comprising exposing a non-silver halide photosensitive layer comprising, light insensitive nuclei and a compound or combination of compounds which upon exposure to light forms or releases a desensitizing agent which causes the nuclei to form deactivated sites for physical development and physically developing the photosensitive layer.

15. A process of claim 14 for preparing a positive silver image comprising physically developing the active sites employing a developing solution containing a soluble silver salt.

16. A process of claim 14 in which the nuclei comprise colloidal silver nuclei.

17. A process of claim 14 in which the combination of compounds is a mixture of a light sensitive azide and a DIR coupler which upon exposure to light causes the nuclei to form deactivated sites for physical development.

18. A process of claim 14 in which the compound is a light sensitive polysulfide compound which upon exposure to light causes the nuclei to form deactivated sites for physical development.

19. A process of claim 14 in which the combination of compounds is a mixture of a light sensitive 4-azido-3- methyl-N,N-diethylaniline and a DI'R coupler which upon exposure to light causes the nuclei to form deactivated sites for physical development.

20. A process of claim 14 in which the compound is a light sensitive polysulfide compound having the following structure:

S-S-S HaC- CH:

which upon exposure to light causes the nuclei to form deactivated sites for physical development.

References Cited by the Examiner UNITED STATES PATENTS Documentation, volume 8, April 1957, pages 81-88.

NORMAN G. TORCHIN, Primary Examiner.

C. E. DAVIS, Assistant Examiner. 

1. A NON-SILVER HALIDE PHOTOGRAPHIC ELEMENT COMPRISING A SUPPORT HAVING THEREON LIGHT INSENSITIVE PHYSICALLY DEVELOPABLE NUCLEI AND A COMPOUND OR COMBINATION OF COMPOUNDS WHICH UPON EXPOSURE TO LIGHT FORMS OR RELEASES A DESENSITIZING AGENT WHICH CAUSES THE NUCLEI TO BE DEACTIVATED FOR PHYSICAL DEVELOPMENT. 